1. Field of the Invention
The present invention relates to a spindle motor and more specifically to a disk drive apparatus using the spindle motor.
2. Description of the Related Art
Some known motors of disk drive apparatuses include bearing mechanisms using fluid dynamic pressure. In some spindle motors (hereinafter referred to simply as “motors”), a gap is defined between an annular member fixed to a shaft portion and a sleeve portion of a rotating portion positioned below the annular member. In some such motors, a seal portion having a surface of a lubricating oil defined therein is defined around the annular member. The seal portion is, for example, covered with a cap member fixed to the annular member.
When the annular member is press fitted to the shaft portion during assemblage of the motor, an outer circumferential surface of the shaft portion or an inner circumferential surface of the annular member may become flawed. If a flaw occurs, the lubricating oil in the gap defined between the annular member and the sleeve portion may leak upwardly out of the annular member through the flaw. Therefore, an operation of sealing a gap between the annular member and the shaft portion is required. Accordingly, there is a demand for a structure designed to easily prevent the lubricating oil from leaking out through the gap between the annular member and the shaft portion.